During the prior funding cycle, the goal of establishing capabilities for the genetic correction of several human genodermatoses was achieved by this group using model systems. As this advance is extended toward human trials, however, the complicated, costly and traumatic features of ex vivo gene transfer are increasingly evident. New approaches to introduce molecular therapies directly into intact skin that do not require tissue harvesting, growth in culture and regrafting represent the next level of needed advances. To address this, plans are proposed to develop the capability for direct delivery of genetic and protein therapeutics to skin using human tissue models of epidermolysis bullosa (EB) and epidermal cancer as prototypes of inherited and acquired human skin disease. First, because they still offer the most efficient means of gene transfer, we will develop capabilities for direct viral vector gene transfer to human skin. To do this, they will use the feline immunodeficiency (FIV) and human immunodeficiency virus (I HV) based lentiviral vectors as well as adeno associated virus (AAV) because they represent complementary approaches to achieve durable genomic integration directly into human skin tissue. Second, due to its attractive safety, cost and stability, the capability for non-viral vector gene transfer to skin will be developed. In doing this, they will attempt to address the two major problems plaguing this approach, namely transience of plasmid retention and low efficiency of gene transfer. To increase persistence, they will use new non-viral transposase and integrase-based methods of plasmid genomic integration. To boost efficiency, they will link DNA elements to newly characterized protein transduction sequences (PTS). Finally, because of its complementary strengths to genetic therapies and its more direct translation to conventional therapeutics, the capability for direct polypeptide delivery to human skin will be developed. Using PTS they have recently shown capable of traversing the cutaneous barrier and entering all cells within human skin, they plan to develop the capability to deliver both small peptides and larger proteins in corrective models of human epidermal neoplasia and EB. At the end of the proposed funding period, they hope to have developed capabilities to deliver new molecular therapeutics directly to skin tissue and to have established their potential utility using models of inherited and neoplastic skin disease.